Recently thanks to the wide spread of digital apparatuses exclusively for photography such as video cameras and digital video recorders as well as camera-imbedded mobile terminals and mp3 players, the number of users who create digital data such as videos has sharply increased.
Accordingly, the amount of digital data created has drastically increased as well and this has requested the necessity to build a system which may systematically manage and use-enormous amount of data.
To perform the management of the digital data and make users use such data more easily, technologies for granting a tag to the digital data by recognizing a person in the digital data were suggested and a variety of methods which extract a tag from the digital data with a higher accuracy are attempted. Herein, “a tag” may be understood as additional data attached to the digital data for rapid access or search to data and it is generally composed of a series of characters or numbers, or a combination of characters and numbers.
As such, it would be possible to attach a tag (i.e., a person tag) inclusive of the information on the recognized persons in the digital data, thereby managing the digital data systematically.
Many users are creating digital data and systematically managing the created digital data by using online content management services such as a blog or an online social network like Cyworld™. In case a digital data to which a tag is attached is uploaded through a content management service, the digital data may be transmitted to a server for the content management service and then recorded in a database of the server. Thereafter, the recorded digital data may be used to recognize faces of persons to be included in digital data which will be uploaded in the future.
For the reasons that latest digital devices have a very many pixels, to make better quality of digital data and accordingly a file size of the digital data is on increase, there was problem: if the digital data, e.g., an image, is transmitted to the content management server, it could require a lot of memory capacity and processing time for processing the image.
In addition, there was another problem that operations were extremely increasing in order to recognize a face of a person included in a newly created digital data because it was necessary to match the face appearing in the newly created digital data with those appearing in a lot of pictures recorded in the server.